Until now, our use case for the visitor has been to take a stream of bytes
representing a type stream, deserialize the records in sequence, and do
something with them, where "something" is determined by how the user
implements a particular set of callbacks on an abstract class.
For actually writing PDBs, however, we want to do the reverse. We have
some kind of description of the list of records in their in-memory format,
and we want to process each one. Perhaps by serializing them to a byte
stream, or perhaps by converting them from one description format (Yaml)
to another (in-memory representation).
This was difficult in the current model because deserialization and
invoking the callbacks were tightly coupled.
With this patch we change this so that TypeDeserializer is itself an
implementation of the particular set of callbacks. This decouples
deserialization from the iteration over a list of records and invocation
of the callbacks. TypeDeserializer is initialized with another
implementation of the callback interface, so that upon deserialization it
can pass the deserialized record through to the next set of callbacks. In
a sense this is like an implementation of the Decorator design pattern,
where the Deserializer is a decorator.
This will be useful for writing Pdbs from yaml, where we have a
description of the type records in Yaml format. In this case, the visitor
implementation would have each visitation callback method implemented in
such a way as to extract the proper set of fields from the Yaml, and it
could maintain state that builds up a list of these records. Finally at
the end we can pass this information through to another set of callbacks
which serializes them into a byte stream.
Reviewed By: majnemer, ruiu, rnk
Differential Revision: https://reviews.llvm.org/D23177
llvm-svn: 277871
MappedBlockSTream can work with any sequence of block data where
the ordering is specified by a list of block numbers. So rather
than manually stitch them together in the case of the FPM, reuse
this functionality so that we can treat the FPM as if it were
contiguous.
Reviewed By: ruiu
Differential Revision: https://reviews.llvm.org/D23066
llvm-svn: 277609
I examined a few PDBs and all of them treated pages for stream 0
are unused, thus they were unmarked in their free page bitmap.
I think we should do the same thing for compatibility.
Differential Revision: https://reviews.llvm.org/D23047
llvm-svn: 277545
The FPM is split at regular intervals across the MSF file, as the MS code
suggests. It turns out that the value of the interval is precisely the
block size. If the block size is 4096, then there are two Fpm pages every
4096 blocks.
So here we teach the PDBFile class to parse a split FPM, and also add more
options when dumping the FPM to display some additional information such
as orphaned pages (pages which the FPM says are allocated, but which
nothing appears to use), use after free pages (pages which the FPM says
are not allocated, but which are referenced by a stream), and multiple use
pages (pages which the FPM says are allocated but are used more than
once).
Reviewed By: ruiu
Differential Revision: https://reviews.llvm.org/D23022
llvm-svn: 277388
Previously this change was submitted from a Windows machine, so
changes made to the case of filenames and directory names did
not survive the commit, and as a result the CMake source file
names and the on-disk file names did not match on case-sensitive
file systems.
I'm resubmitting this patch from a Linux system, which hopefully
allows the case changes to make it through unfettered.
llvm-svn: 277213
In a previous patch, it was suggested to use all caps instead of
rolling caps for initialisms, so this patch changes everything
to do this.
llvm-svn: 277190
This was a pure virtual base class whose purpose was to abstract
away the notion of how you retrieve the layout of a discontiguous
stream of blocks in an Msf file. This led to too many layers of
abstraction making it difficult to figure out what was going on
and extend things. Ultimately, a stream's layout is decided by
its length and the array of block numbers that it lives on. So
rather than have an abstract base class which can return this in
any number of ways, it's more straightforward to simply store them
as fields of a trivial struct, and also to give a more appropriate
name.
This patch does that. It renames IMsfStreamData to MsfStreamLayout,
and deletes the 2 concrete implementations, DirectoryStreamData
and IndexedStreamData. MsfStreamLayout is a trivial struct
with the necessary data.
llvm-svn: 277018
This provides a better layering of responsibilities among different
aspects of PDB writing code. Some of the MSF related code was
contained in CodeView, and some was in PDB prior to this. Further,
we were often saying PDB when we meant MSF, and the two are
actually independent of each other since in theory you can have
other types of data besides PDB data in an MSF. So, this patch
separates the MSF specific code into its own library, with no
dependencies on anything else, and DebugInfoCodeView and
DebugInfoPDB take dependencies on DebugInfoMsf.
llvm-svn: 276458
Block 1 and 2 of an MSF file are bit vectors that represent the
list of blocks allocated and free in the file. We had been using
these blocks to write stream data and other data, so we mark them
as the free page map now. We don't yet serialize these pages to
the disk, but at least we make a note of what it is, and avoid
writing random data to them.
Doing this also necessitated cleaning up some of the tests to be
more general and hardcode fewer values, which is nice.
llvm-svn: 275629
Previously we would read a PDB, then write some of it back out,
but write the directory, super block, and other pertinent metadata
back out unchanged. This generates incorrect PDBs since the amount
of data written was not always the same as the amount of data read.
This patch changes things to use the newly introduced `MsfBuilder`
class to write out a correct and accurate set of Msf metadata for
the data *actually* written, which opens up the door for adding and
removing type records, symbol records, and other types of data to
an existing PDB.
llvm-svn: 275627
There is no polymorphism here, and StreamRef already contains a
StreamInterface pointer. Dropping the base class makes StreamRef more
transparent to the compiler, for example it can find unused variables.
llvm-svn: 275013
This allows better catching of compiler errors since we can use
the override keyword to verify that methods are actually
overridden.
Also in this patch I've changed from storing a boolean Error
code everywhere to returning an llvm::Error, to propagate richer
error information up the call stack.
Reviewed By: ruiu, rnk
Differential Revision: http://reviews.llvm.org/D21410
llvm-svn: 272926
In order to efficiently write PDBs, we need to be able to make a
StreamWriter class similar to a StreamReader, which can transparently deal
with writing to discontiguous streams, and we need to use this for all
writing, similar to how we use StreamReader for all reading.
Most discontiguous streams are the typical numbered streams that appear in
a PDB file and are described by the directory, but the exception to this,
that until now has been parsed by hand, is the directory itself.
MappedBlockStream works by querying the directory to find out which blocks
a stream occupies and various other things, so naturally the same logic
could not possibly work to describe the blocks that the directory itself
resided on.
To solve this, I've introduced an abstraction IPDBStreamData, which allows
the client to query for the list of blocks occupied by the stream, as well
as the stream length. I provide two implementations of this: one which
queries the directory (for indexed streams), and one which queries the
super block (for the directory stream).
This has the side benefit of vastly simplifying the code to parse the
directory. Whereas before a mini state machine was rolled by hand, now we
simply use FixedStreamArray to read out the stream sizes, then build a
vector of FixedStreamArrays for the stream map, all in just a few lines of
code.
Reviewed By: ruiu
Differential Revision: http://reviews.llvm.org/D21046
llvm-svn: 271982
This is the simplest possible patch to get some kind of YAML
output. All it dumps is the MSF header fields so that in
theory an empty MSF file could be reconstructed.
Reviewed By: ruiu, majnemer
Differential Revision: http://reviews.llvm.org/D20971
llvm-svn: 271939
The data strucutre in the new FPO stream is described in the
PE/COFF spec. There is one record per function if frame pointer
is omitted.
Differential Revision: http://reviews.llvm.org/D20999
llvm-svn: 271926
This opens the door to introducing a YAML outputter which can be
used for machine consumption. Currently the yaml output style
is unimplemented and returns an error if you try to use it.
Reviewed By: rnk, ruiu
Differential Revision: http://reviews.llvm.org/D20967
llvm-svn: 271712
